Questions about the metaphysics of causation may be usefully divided into questions about the objects that are causally related, and questions about the causal relations themselves. For instance, is causation merely a physical concept? What is the connection between causation and probability? According to Wesley Salmon, an analysis of causation in terms of physical and causal relations of propensity is possible. But he replaces the notion of necessity with what he calls propensity. This approach to causality is consistent with a probabilistic approach. Another approach would be to reduce such relations to the physical causation. These questions should be resolved. As it turns out, in order to resolve these fundamental and metaphysical disputes, we can turn to a concept of causation that has been discussed within the Islamic philosophy. This approach treats causality as a rational and philosophical notion, and, in contrast to the probabilistic approach, it retains the necessity of causal relations.